The Marshall Excelsior MER425H-24 24" LP Pigtail Hose - 1/4" Male Inverted Flare provides a safe, user-friendly connection from your Marshall Excelsior MEGR-253/253H regulator to a standard LP gas cylinder without the use of a wrench. The easy to tighten nylon nut swivels on a connector fitting that is heat sensitive. Between 240 F and 300 F the brass nipple displaces (approximately 1/4”) closing the cylinder valve module and stopping the flow of gas from the container. Inside the brass nipple is a flow-limiting device designed to sense excess gas flow. If excessive gas flow is detected, the RV Thermo Pigtail will shut down the flow to a maximum of 10 SCFH (by-pass flow).